Check if IndexedDB database exists

Question

Is there a way to check if an IndexedDB database already exists? When a program tries to open a database that does not exists the database is created. The only way that I can think of is something like the following, where I test if an objectStore already exists, if it doesn't, the database is deleted:

var dbexists=false; var request = window.indexedDB.open("TestDatabase"); request.onupgradeneeded = function(e) {     db = e.target.result;     if (!db.objectStoreNames.contains('todo')) {        db.close();        indexedDB.deleteDatabase("TestDatabase");     } else {        dbexists=true;     } } 

Answer 1

In the onupgradeneeded callback you can check the version. (e.target.result.oldversion). If it is 0, the db didn't exist.

Edit: After some investigation. You can't be 100% sure if a new db is created. 1 thing I am sure of is the fact that you can only work with an indexeddb if it has a version 1 or higher. I believe that a db can exist and have a version 0 (The only fact is you can't work with it and the onupgradeneeded event will be called).

I have build my own indexeddbviewer. In that I open the indexeddb without version and if I come in to the onupgradeneeded event, that means the db doesn't exist. In that case I call the abort so it doesn't upgrade to a version 1. This is the way I check it.

var dbExists = true; var request = window.indexeddb.open("db"); request.onupgradeneeded = function (e){     e.target.transaction.abort();     dbExists = false; } 

but as mentioned. It is possible that the db will continue to exist in that case, but the onupgradeneeded will always be called

Answer 2

With ES6 you can find an IndexedDB database by its name using the following code:

const dbName = 'TestDatabase'; const isExisting = (await window.indexedDB.databases()).map(db => db.name).includes(dbName);